RoundupReads The Surveyors—precursors to human boot prints on the Moon

The Surveyors—precursors to human boot prints on the Moon

2017-11-08
The Surveyors were a series of robotic landers managed by NASA’s Jet Propulsion Laboratory designed to make soft landings on the Moon to study lunar surface properties and act as precursors for future human landings. They provided ground-level information at potential Apollo landing sites that, combined with orbital imagery from lunar orbiters, increased our knowledge of the Moon in preparation for human missions.

Surveyor 6, the sixth in a series of seven spacecraft, launched from Cape Canaveral on an Atlas-Centaur rocket on Nov. 7, 1967. It landed successfully on the Moon three days later at Sinus Medii in the center of the Moon’s visible hemisphere. The craft began sending back images of its landing site and analyzing the lunar soil’s composition.

On Nov. 17, 1967, Surveyor’s engines fired for 2.5 seconds, lifting the spacecraft 12 feet high and moving it 8 feet west of its original landing site—the first powered liftoff from another celestial body. This successful engineering test showed that its rockets could be restarted on the Moon, further propelling a human mission.

By the time its mission ended on Dec. 14, 1967, Surveyor 6 had returned approximately 30,000 pictures of itself and its surroundings while still studying the chemical composition of the lunar surface. The results of the experiments showed that the surface had a basaltic composition, similar to that found at the Surveyor 5 landing site, indicating that lunar maria shared similar geologic histories.

Engineering and soil mechanics data confirmed findings from earlier Surveyors that the bearing strength of the surface was more than adequate to support human landings. In February 1968, the NASA Apollo Site Selection Board chose an area near Surveyor 6’s location as one of five potential landing zones for the first human mission, meeting suitability criteria such as smooth flat terrain and a clear approach path. With Surveyor 6, the survey of potential landing areas for Apollo was completed, allowing Surveyor 7, the last in the series scheduled to fly in January 1968, to be targeted for a more scientifically diverse site: the crater Tycho.

Surveyor 6 brought NASA one step closer to achieving the Moon landing before the end of the decade.

For more on the Surveyor program, please visit: https://nssdc.gsfc.nasa.gov/planetary/lunar/surveyor.html

Composite of images taken by Surveyor 6 of its landing site in the Sinus Medii.
Composite images taken by Surveyor 6 of its landing site in the Sinus Medii. Image Credit: NASA 

 
John Uri
NASA Johnson Space Center
 
Night launch of Surveyor 6. Image Credit: NASA
A nearly identical Surveyor 3 on the Moon as photographed during a visit by Apollo 12 astronauts. Image Credit: NASA